首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   632篇
  免费   14篇
  国内免费   8篇
安全科学   27篇
废物处理   25篇
环保管理   149篇
综合类   49篇
基础理论   165篇
环境理论   1篇
污染及防治   135篇
评价与监测   64篇
社会与环境   24篇
灾害及防治   15篇
  2023年   5篇
  2022年   5篇
  2021年   8篇
  2020年   9篇
  2019年   4篇
  2018年   16篇
  2017年   15篇
  2016年   17篇
  2015年   9篇
  2014年   28篇
  2013年   43篇
  2012年   26篇
  2011年   35篇
  2010年   33篇
  2009年   26篇
  2008年   39篇
  2007年   34篇
  2006年   40篇
  2005年   26篇
  2004年   16篇
  2003年   29篇
  2002年   21篇
  2001年   10篇
  2000年   9篇
  1999年   5篇
  1998年   13篇
  1997年   8篇
  1996年   13篇
  1995年   11篇
  1994年   15篇
  1993年   11篇
  1992年   3篇
  1991年   9篇
  1990年   4篇
  1989年   5篇
  1988年   4篇
  1987年   3篇
  1985年   7篇
  1984年   6篇
  1983年   6篇
  1982年   8篇
  1980年   2篇
  1978年   3篇
  1976年   5篇
  1974年   1篇
  1973年   1篇
  1972年   1篇
  1971年   1篇
  1966年   1篇
  1964年   1篇
排序方式: 共有654条查询结果,搜索用时 312 毫秒
31.
The LASTFIRE test is intended for the evaluation of foams used in extinguishing fires of flammable and combustible liquids in storage tanks in refinery and oil related facilities. The purpose of this study is to find, experimentally, an alternative fuel to be used in the LASTFIRE test, as a replacement for the heptane fuel, which is normally used in this test. Beside heptane, three other fuels are tested in the current study: diesel, jet A1 and kerosene. The study involved performing the LASTFIRE test, using each of the fuels and then comparing the results. The same foam is used as an extinguishing agent for all the tests and for each fuel, tests are conducted three times with separate foam discharging nozzles: semi-aspirated, aspirated and system. Using a commonly used scoring system, the results of the four fuels are evaluated. Any replaceable fuel should obtain the similar score as that is obtained by heptane. The study shows that none of the three alternatives has been judged to be suitable to replace heptane, in the LASTFIRE test.  相似文献   
32.
Summary The nature and evidence of the gaia and geochemical hypotheses describing the dynamics of the ecosphere are reviewed. In particular, the ways in which the unorthodox gaia hypothesis challenges the orthodox global models of geochemistry are discussed in the context of the logic and sociology of science. It is argued that the gaia hypothesis offers environmental scientists a working hypothesis of unusual promise, especially for understanding the processes underlying the long-term dynamics of the global environmental system.Dr Ian Moffatt is a member of the staff of the Department of Environmental Science at the University of Stirling.  相似文献   
33.
34.
Two paradigms of professional development in environmental education   总被引:3,自引:0,他引:3  
Summary In environmental education in this information age, it is particularly important to adopt the approach of enquiring critically into the environmental, educational and social values informing environmental, educational and social actions when and where required, rather than to simply adopt the approach of emphasising the acquisition and retention of information of an alleged universal type — information drawn from the stockpile of objective knowledge collected by others. This paper argues that to achieve this aim, environmental education in an information age requires aparadigm shift in the areas of professional development — a shift from a paradigm of information technology to a paradigm of information critique. A perspective on the form of this paradigm shift in the particular field of professional development in environmental education is the subject of this paper.Dr Ian Robottom is Senior Lecturer in the Curriculum Studies Centre of the School of Education, at Deakin University, Australia. His main interests lie in teacher education, educational enquiry, and environmental education. He conducts an off-campus environmental education course (B.Ed level) for practising teachers studying at a distance, is a member of the Council of the Australian Association for Environmental Education., and Editor of theAustralian Journal of Environmental Education.  相似文献   
35.
The EEC Shellfish Directive is a policy designed to protect and, where necessary, improve the quality of designated shellfish waters. Its implementation within the UK, however, has had no effect upon water quality for two reasons. First, the policy has important defects, having ambiguities concerning public health provisions and lacking designation criteria. Second, UK government has sought to achieve formal compliance, while at the same time ensuring that its full financial impact on public expenditure has been contained. Consequently, only those fisheries which already comply with water quality standards have been designated. Within Wales, one fishery has been designated, while other, commercially more important, but grossly contaminated shellfisheries have not.  相似文献   
36.
37.
Safety climate   总被引:12,自引:0,他引:12  
Safety climate, the objective measurement of attitudes and perceptions toward Occupational Health & Safety (OH&S) issues, has been largely ignored and measures such as lost time and frequency rate have been used to determine the efficacy of OH&S programs. Yet, it is clear that measuring the precursors of accidents identified in a safety climate analysis provides a powerful proactive management tool. This paper reports on safety climate factors found in clerical and service organizations in Australia. Concurrent validity studies are reported. In contradistinction to published studies, it is argued that safety climate factors are not stable across organizations. The significance of this for planning and assessing the efficacy of OH&S programs is discussed. It is concluded that although safety climate factors are not stable, the safety climate factor pattern identified in organizations provides a powerful management tool for designing OH&S programs.  相似文献   
38.
The impact of urbanization on timber harvesting in the south central United States was investigated. Geo-referenced Census and Forest Inventory Analysis (FIA) data were combined using a geographic information system (GIS) in order to examine the effects of various demographic and biophysical forest inventory characteristics on timber harvesting. These effects were estimated for intermediate and final harvests using a multinomial logit model. The probability for both types of harvests decreased with increasing population density, decreasing forest size, and decreasing distance to urban areas; however, the reduction in intermediate harvests was greater for each variable. Harvesting rates decreased by as much as 19% as population densities increased or distance to urban areas decreased. The results indicated that active forest management is curtailed far beyond the urban boundary. In order to model the impact of urbanization adequately, timber supply projections must also account for its impact on harvesting frequencies in surrounding areas.  相似文献   
39.
Applications of in situ agrobiodiversity conservation practices within agricultural production systems have the potential to reduce the risks of agricultural modernisation and enhance sustainable development. The aims and approaches for in situ conservation differ according to the requirements of communities and nations. Approaches to in situ conservation in the decade after the Convention of Biological Diversity are reviewed within the contexts of marginal agricultural systems in Nepal, Turkey and Switzerland. Numerous approaches are currently utilised, including: the informal de facto retention of agrobiodiversity; the provision of state assistance; the marketing of agrobiodiversity products; the use of technological innovations to develop local diversity; the establishment of conservation reserves; community assistance programmes and the raising of awareness of the issue amongst all sectors of societies. Emerging complementary in situ approaches applicable in the rural margins suggest a framework for effectively conserving agrobiodiversity by working with local people.  相似文献   
40.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号